High-Performance Black Screw, Zinc Plated

Non tapping screw are Machine screw , the pieceworker to be fastened must be tapped with taps in the Screw hole in advance to match the screw threads. The difference between tooth screws and other screws depends on whether they can be used together with nuts. Tooth screws can be used with nuts. And relative to the screws of other teeth, there are self-tapping screws. The nut of this kind of screw has no bow teeth. As for the standard teeth and fine teeth are only different pitch,...